1) Best sources for tanks, regulators, controllers etc.

This is what I bought:

Rapids Wholesale - Co2 kits - 5-lb new steel tank with dual guage regulators
$99

http://rapidswholesale.net/Merchant2/merchant.mv"http://rapidswholesale.net/
Merchant2/merchant.mv?

Florida driftwood - needle valve used in medical gases $19.50

http://www.floridadriftwood.com/product.asp?3=51